This invention relates to a buttressing pledget. The buttressing pledget is manufactured from a synthetic elastomeric material. The elastomeric material can be nonporous and/or a silicone rubber. The pledget can also be radiolucent or radiopaque. The buttressing pledget can be made radiopaque by the addition of barium sulfate. This invention also relates to a buttressing pledget in combination with a surgical suture or ligature.
The material used to manufacture a surgical pledget has remained relatively constant in the prior art. Probably to avoid irritation to the tissue, the surgical community prefers a soft, loose, fibrous material. For example, please see U.S. Pat. No. 3,825,007 entitled "Pledgets" which issued Jul. 23, 1974; U.S. Pat. No. 4,405,324 entitled "Absorbent Cellulosic Structures" which issued Sep. 20, 1983; and the definition of pledget in ATTORNEY'S DICTIONARY OF MEDICINE and WORD FINDER, J. Schmidt vol. 3 page P-217, Matthew Bender, N.Y. 1988. The patents are incorporated herein by reference. A coreless braided and woven pledget are also known in the prior art. Both the braided and the woven pledget are manufactured from a Dacron* (DuPont, Del., USA) fiber.
As the surgical community and wound closure industry sought better solutions to health problems, new uses of the pledget began to appear. One of these new uses was a buttress during surgery. This new use gave rise to the buttressing pledget as an article of manufacture, which has achieved a separate status in the art. As an example of the development of the buttressing pledget art, please see U.S. Pat. Nos. 4,164,046 FIG. 6 element 40; 4,549,545; and, generally, 4,823,794. For the packaging of a buttressing pledget in combination with a surgical suture, please see U.S. Pat. No. 4,034,850. These patents are incorporated herein by reference.
The claims in this application are limited to a buttressing pledget. The claimed pledgets can be molded or extruded and have several advantages over the known prior art pledgets. One advantage is that the buttressing pledgets described in this application can be nonfibrous. Because they can be nonfibrous, the problem of exfoliation is essentially eliminated. Another advantage is that the molded or extruded buttressing pledgets can be nonporous. Thus, the problem of tissue ingrowth, which can limit or at least interfere with the wound closure process, is essentially eliminated. For a contrast of these two advantages over the prior art, please see U.S. Pat. No. 4,549,545, column 1 lines 28 to 40 and 46 to 49.
Yet another advantage of a molded or extruded buttressing pledget is that a variety of shapes can be obtained. The availability of various shapes may enhance the efficacy of a known surgical procedure. The shapes described in two dimensions include but are not limited to square, rectangular, round, oval and elliptical, and in three dimensions, the shapes include tubular. Another advantage of a molded or extruded pledget is that it can be manufactured with a more consistent thickness. This advantage can be critical, especially where the pledget is small in size and/or the surgical procedure is major, such as a cardiovascular operation.
Still another advantage is that the buttressing pledget can be manufactured from a radiopaque material. The advantage of a radiopaque material is apparent to the surgical user. For example, in cardiovascular surgery it may be important, if not critical, to know the postoperative location of the pledgets that were used. Knowing the postoperative location, the surgeon or medical technologist can make a prognosis of the patient's wound healing process.
An X-ray photograph, a CAT scan or a similar image can identify the pledget's radiopaque material, and thus show the surgeon or technologist the location of the piedgets. This in turn can indicate that the suturing or stapling technique used by the surgeon is efficacious to the wound healing process.
A further advantage is that the holes formed through a molded or extruded pledget of this invention can be built up around the edges such that the pledget is structurally stronger in these places than the prior art buttressing pledgets. For contrast, please see the edges of the buttressing pledget openings 24, 26 and 42 as shown in U.S. Pat. No. 4,823,794 FIGS. 1 and 2, or the opening in the pledget 16 as shown in U.S. Pat. No. 4,549,545 FIG. 1.
A natural rubber has been disclosed for use as a latex in a neuropledget. The latex is sprayed onto a surface to form a layer. The neuropledget is manufactured by combining the latex layer with an absorbent fibrous material. Please see U.S. Pat. No. 3,825,007, which is more fully cited above. Because the utility disclosed is not a buttressing pledget, because the natural rubber has to be formed into a latex, because the latex is sprayed onto a layer, because the layer is combined with a fibrous composition, this reference is not material to the inventions claimed in this application. Other prior art compositions that have been used to manufacture buttressing pledgets include a Teflon* (DuPont, Del., USA) or polyurethane fibrous mat. Please see U.S. Pat. Nos. 4,549,545 and 4,823,794, which are also cited above.
For a description of a pledget comprising a radiopaque material (Pantopaque*), please see the Journal of Neurosurgery (J. Neurosurg) vol. 44 pages 753-756, 1976. The use of the radiopaque pledget described in this journal article is limited to an arterial embolus and specifically the embolization of an arteriovenous malformation.
For a disclosure of nonpledget medical uses of a silicone rubber, please see Table 3 under the title "Medical Applications" in Encyclopedia Of Polymer Science And Engineering, 2nd Edition, J. Kroschwitz, Ed., vol. 9, page 498, J. Wiley & Sons, NY 1987. It is not seen in any of these uses where there is a teaching or suggestion of a buttressing pledget.
In summary, the surgical community continues to seek a buttressing pledget which will make surgical procedures more efficacious. Please see, e.g., the articles and commentary in The Annals of Thoracic Surgery (Ann Thorac Burg) vol. 41 pages 219-221 and vol. 42 pages 601-603, both published in 1986, and The Journal of Thoracic and Cardiovascular Burgery (J Thorac Cardiovasc Burg) vol. 94 pages 430-433 and 442-443, 1987. These publications are incorporated herein by reference.